vbagx/source/vba/pixel.cpp

// VisualBoyAdvance - Nintendo Gameboy/GameboyAdvance (TM) emulator.
// Copyright (C) 1999-2003 Forgotten
// Copyright (C) 2004 Forgotten and the VBA development team

// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2, or(at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software Foundation,
// Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

#include "System.h"

extern int RGB_LOW_BITS_MASK;

void Pixelate(u8 *srcPtr, u32 srcPitch, u8 *deltaPtr,
              u8 *dstPtr, u32 dstPitch, int width, int height)
{
  u8 *nextLine, *finish;
  u32 colorMask = ~(RGB_LOW_BITS_MASK | (RGB_LOW_BITS_MASK << 16));

  nextLine = dstPtr + dstPitch;

  do
    {
      u32 *bP = (u32 *) srcPtr;
      u32 *xP = (u32 *) deltaPtr;
      u32 *dP = (u32 *) dstPtr;
      u32 *nL = (u32 *) nextLine;
      u32 currentPixel;
      u32 nextPixel;
      u32 currentDelta;
      u32 nextDelta;

      finish = (u8 *) bP + ((width+2) << 1);
      nextPixel = *bP++;
      nextDelta = *xP++;

      do
        {
          currentPixel = nextPixel;
          currentDelta = nextDelta;
          nextPixel = *bP++;
          nextDelta = *xP++;

          if ((nextPixel != nextDelta) || (currentPixel != currentDelta))
            {
              u32 colorA, colorB, product;

              *(xP - 2) = currentPixel;
#ifdef WORDS_BIGENDIAN
              colorA = currentPixel >> 16;
              colorB = currentPixel & 0xffff;
#else
              colorA = currentPixel & 0xffff;
              colorB = currentPixel >> 16;
#endif
              product = (((colorA & colorMask) >> 1) & colorMask) >> 1;

#ifdef WORDS_BIGENDIAN
              *(nL) = (product << 16) | (product);
              *(dP) = (colorA << 16) | product;
#else
              *(nL) = product | (product << 16);
              *(dP) = colorA | (product << 16);
#endif

#ifdef WORDS_BIGENDIAN
              colorA = nextPixel >> 16;
#else
              colorA = nextPixel & 0xffff;
#endif
              product = (((colorB & colorMask) >> 1) & colorMask) >> 1;
#ifdef WORDS_BIGENDIAN
              *(nL + 1) = (product << 16) | (product);
              *(dP + 1) = (colorB << 16) | (product);
#else
              *(nL + 1) = (product) | (product << 16);
              *(dP + 1) = (colorB) | (product << 16);
#endif
            }

          dP += 2;
          nL += 2;
        }
      while ((u8 *) bP < finish);

      deltaPtr += srcPitch;
      srcPtr += srcPitch;
      dstPtr += dstPitch << 1;
      nextLine += dstPitch << 1;
    }
  while (--height);
}

void Pixelate32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
                u8 *dstPtr, u32 dstPitch, int width, int height)
{
  u8 *nextLine, *finish;
  u32 colorMask = ~RGB_LOW_BITS_MASK;

  nextLine = dstPtr + dstPitch;

  do
    {
      u32 *bP = (u32 *) srcPtr;
      //    u32 *xP = (u32 *) deltaPtr;
      u32 *dP = (u32 *) dstPtr;
      u32 *nL = (u32 *) nextLine;
      u32 currentPixel;
      u32 nextPixel;

      finish = (u8 *) bP + ((width+1) << 2);
      nextPixel = *bP++;

      do
        {
          currentPixel = nextPixel;
          nextPixel = *bP++;

          u32 colorA, colorB, product;

          colorA = currentPixel;
          colorB = nextPixel;

          product = (((colorA & colorMask) >> 1) & colorMask) >> 1;
          *(nL) = product;
          *(nL+1) = product;
          *(dP) = colorA;
          *(dP+1) = product;

          nextPixel = *bP++;
          colorA = nextPixel;
          product = (((colorB & colorMask) >> 1) & colorMask) >> 1;
          *(nL + 2) = product;
          *(nL + 3) = product;
          *(dP + 2) = colorB;
          *(dP + 3) = product;

          dP += 4;
          nL += 4;
        }
      while ((u8 *) bP < finish);

      srcPtr += srcPitch;
      dstPtr += dstPitch << 1;
      nextLine += dstPitch << 1;
    }
  while (--height);
}